Question

A typical incandescent bulb has an efficiency of about 10%. What current is needed for a bulb with a resistance of (1.5×10^2) Ω  to output power of 6.0 W?

Answer 1

Solution;

$P=I^2R$

$6=I^2(1.5×10^2)$

$I^2=0.4$

$I=0.6324A$